Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Theoretical and experimental evidence for a post-perovskite phase of MgSiO3 in Earth's D″ layer

Abstract

The Earth's lower mantle is believed to be composed mainly of (Mg,Fe)SiO3 perovskite, with lesser amounts of (Mg,Fe)O and CaSiO3 (ref. 1). But it has not been possible to explain many unusual properties of the lowermost 150 km of the mantle (the D″ layer) with this mineralogy. Here, using ab initio simulations and high-pressure experiments, we show that at pressures and temperatures of the D″ layer, MgSiO3 transforms from perovskite into a layered CaIrO3-type post-perovskite phase. The elastic properties of the post-perovskite phase and its stability field explain several observed puzzling properties of the D″ layer: its seismic anisotropy2, the strongly undulating shear-wave discontinuity at its top3,4,5,6 and possibly the anticorrelation between shear and bulk sound velocities7,8.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Structure of the post-perovskite phase of MgSiO3 (calculated at 120 GPa).
Figure 2: Stability of the post-perovskite phase.
Figure 3: Experimental powder diffraction pattern at 118 GPa and 300 K matching the predicted lattice parameters.

References

  1. Fiquet, G. Mineral phases of the Earth's mantle. Z. Krist. 216, 248–271 (2001)

    CAS  Google Scholar 

  2. Panning, M. & Romanowicz, B. Inferences on flow at the base of Earth's mantle based on seismic anisotropy. Science 303, 351–353 (2004)

    ADS  CAS  Article  Google Scholar 

  3. Lay, T. & Helmberger, D. V. A shear velocity discontinuity in the lower mantle. Geophys. Res. Lett. 10, 63–66 (1983)

    ADS  Article  Google Scholar 

  4. Sidorin, I., Gurnis, M., Helmberger, D. V. & Ding, X. Interpreting D″ seismic structure using synthetic waveforms computed from dynamic models. Earth Planet. Sci. Lett. 163, 31–41 (1998)

    ADS  CAS  Article  Google Scholar 

  5. Sidorin, I., Gurnis, M. & Helmberger, D. V. Evidence for a ubiquitous seismic discontinuity at the base of the mantle. Science 286, 1326–1331 (1999)

    CAS  Article  Google Scholar 

  6. Sidorin, I., Gurnis, M. & Helmberger, D. V. Dynamics of a phase change at the base of the mantle consistent with seismological observations. J. Geophys. Res. 104, 15005–15023 (1999)

    ADS  CAS  Article  Google Scholar 

  7. Su, W. J. & Dziewonski, A. M. Simultaneous inversion for 3-D variations in shear and bulk velocity in the mantle. Phys. Earth Planet. Inter. 100, 135–156 (1997)

    ADS  Article  Google Scholar 

  8. Masters, G. et al. in Earth's Deep Interior: Mineral Physics and Tomography from the Atomic to the Global Scale (ed. Karato, S.-i.) 63–87 (AGU Geophysical Monograph 117, American Geophysical Union, Washington DC, 2000)

    Book  Google Scholar 

  9. Saxena, S. K. et al. Stability of perovskite (MgSiO3) in the Earth's mantle. Science 274, 1357–1359 (1996)

    ADS  CAS  Article  Google Scholar 

  10. Fiquet, G., Dewaele, A., Andrault, D., Kunz, M. & Le Bihan, T. Thermoelastic properties and crystal structure of MgSiO3 perovskite at lower mantle pressure and temperature conditions. Geophys. Res. Lett. 27, 21–24 (2000)

    ADS  CAS  Article  Google Scholar 

  11. Serghiou, G., Zerr, A. & Boehler, R. (Mg,Fe)SiO3-perovskite stability under lower mantle conditions. Science 280, 2093–2095 (1998)

    CAS  Article  Google Scholar 

  12. Shim, S. H., Duffy, T. S. & Shen, G. Y. Stability and structure of MgSiO3 perovskite to 2300-kilometer depth in Earth's mantle. Science 293, 2437–2440 (2001)

    ADS  CAS  Article  Google Scholar 

  13. Ono, S., Ohishi, Y. & Mibe, K. Phase transition of Ca-perovskite and stability of Al-bearing Mg-perovskite in the lower mantle. Am. Mineral. (in the press)

  14. Ono, S., Sata, N. & Ohishi, Y. Phase transformation of perovskite structure in Fe2O3 at high pressures and high temperatures. Am. Mineral. (submitted)

  15. Rodi, F. & Babel, D. Erdalkaliiridium(IV) - oxide: Kristallstruktur von CaIrO3 . Z. Anorg. Allg. Chem. 336, 17–23 (1965)

    CAS  Article  Google Scholar 

  16. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996)

    ADS  CAS  Article  Google Scholar 

  17. Oganov, A. R. & Brodholt, J. P. High-pressure phases in the Al2SiO5 system and the problem of Al-phase in Earth's lower mantle: ab initio pseudopotential calculations. Phys. Chem. Miner. 27, 430–439 (2000)

    ADS  CAS  Article  Google Scholar 

  18. Baroni, S., de Gironcoli, S., Dal Corso, A. & Gianozzi, P. Phonons and related crystal properties from density-functional perturbation theory. Rev. Mod. Phys. 73, 515–562 (2001)

    ADS  CAS  Article  Google Scholar 

  19. Urusov, V. S. Theoretical Crystal Chemistry (Moscow State Univ. Press, Moscow, 1987) [in Russian]

    Google Scholar 

  20. Oganov, A. R., Brodholt, J. P. & Price, G. D. The elastic constants of MgSiO3 perovskite at pressures and temperatures of the Earth's mantle. Nature 411, 934–937 (2001)

    ADS  CAS  Article  Google Scholar 

  21. Oganov, A. R., Brodholt, J. P. & Price, G. D. Ab initio elasticity and thermal equation of state of MgSiO3 perovskite. Earth Planet. Sci. Lett. 184, 555–560 (2001)

    ADS  CAS  Article  Google Scholar 

  22. Ono, S., Hirose, K., Isshiki, M., Mibe, K. & Saito, Y. Equation of state of hexagonal aluminous phase of natural composition to 63 GPa at 300 K. Phys. Chem. Miner. 29, 527–531 (2002)

    ADS  CAS  Article  Google Scholar 

  23. Jeanloz, R. & Williams, Q. The core-mantle boundary region. Rev. Mineral. 37, 241–259 (1998)

    CAS  Google Scholar 

  24. Wentzcovitch, R. M., Karki, B. B., Karato, S. & da Silva, C. R. S. High pressure elastic anisotropy of MgSiO3 perovskite and geophysical implications. Earth Planet. Sci. Lett. 164, 371–378 (1998)

    ADS  CAS  Article  Google Scholar 

  25. Montagner, J.-P. & Nataf, H.-C. A simple method for inverting the azimuthal anisotropy of surface waves. J. Geophys. Res. 91, 511–520 (1986)

    ADS  Article  Google Scholar 

  26. Murakami, M., Hirose, K., Kawamura, K., Sata, N. & Ohishi, Y. Post-perovskite phase transition in MgSiO3 . Science 304, 855–858 (2004)

    ADS  CAS  Article  Google Scholar 

  27. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994)

    ADS  Article  Google Scholar 

  28. Kresse, G. & Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 59, 1758–1775 (1999)

    ADS  CAS  Article  Google Scholar 

  29. Kresse, G. & Furthmüller, J. Efficiency of ab initio total-energy calculations for metals and semiconductors using a plane-wave basis set. Comp. Mater. Sci. 6, 15–50 (1996)

    CAS  Article  Google Scholar 

  30. Gonze, X. et al. First-principles computation of materials properties: the ABINIT software project. Comp. Mater. Sci. 25, 478–492 (2002)

    Article  Google Scholar 

Download references

Acknowledgements

Calculations were performed at CSCS (Manno) and ETH Zurich. We thank P. Ulmer, A.N. Halliday, S. Goes, F. Cammarano, A.B. Thompson and P.J. Tackley for discussions, and Y. Ohishi and N. Sata for experimental support. Synchrotron radiation experiments were performed at the BL10XU, SPring-8.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Artem R. Oganov.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Oganov, A., Ono, S. Theoretical and experimental evidence for a post-perovskite phase of MgSiO3 in Earth's D″ layer. Nature 430, 445–448 (2004). https://doi.org/10.1038/nature02701

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature02701

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing